Christine Lemmer-Webberis the idea federated MUD? It's come up a few times and yes it's an amazing thing to think about
My goal is eventually to be able to implement the full "network spaces desiderata" http://saraswat.org/desiderata.html
Jonkman Microblog is a social network, courtesy of SOBAC Microcomputer Services. It runs on GNU social, version 1.2.0-beta5, available under the GNU Affero General Public License.
All Jonkman Microblog content and data are available under the Creative Commons Attribution 3.0 license.